21143224521 has 12 divisors (see below), whose sum is σ = 30547292100. Its totient is φ = 14092215840.

The previous prime is 21143224519. The next prime is 21143224631. The reversal of 21143224521 is 12542234112.

21143224521 is a `hidden beast` number, since 2 + 114 + 3 + 2 + 24 + 521 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 223652025 + 20919572496 = 14955^2 + 144636^2 .

It is not a de Polignac number, because 21143224521 - 2¹ = 21143224519 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21143229521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 230950 + ... + 309231.

It is an arithmetic number, because the mean of its divisors is an integer number (2545607675).

Almost surely, 2^21143224521 is an apocalyptic number.

It is an amenable number.

21143224521 is a deficient number, since it is larger than the sum of its proper divisors (9404067579).

21143224521 is a wasteful number, since it uses less digits than its factorization.

21143224521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544536 (or 544533 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

Adding to 21143224521 its reverse (12542234112), we get a palindrome (33685458633).

The spelling of 21143224521 in words is "twenty-one billion, one hundred forty-three million, two hundred twenty-four thousand, five hundred twenty-one".